Synthesis And Study Of Polyether No-Phosphate Terpolymer As Scale Inhibitor

This paper mainly focus on research a polyether-based terpolymer antiscalant and the main aim to gain a non-phosphorous, newly, high-effective and environmental friendly agent. The polymeric scale inhibitor and dispersion agent (PAYS) was prepared by graft copolymerization of acrylic acid (AA), allylpolyethoxy carboxylate (APEY) and 2-acrylamido-2-methyl- propanesulfonic acid (AMPS) by using ammonium persulfate as a radical initiator in aqueous solution. The results show that the terpolymer has characteristics of simple preparation process technology, excellent scale inhibition performance and great corrosion inhibition and dispersion.The polymeric scale inhibition and dispersion agents (PAYS) were prepared by graft copolymerization of acrylic acid (AA), allylpolyethoxy carboxylate (APEY) and 2-acrylamido -2-methyl-propanesulfonic acid (AMPS) in aqueous solution, among which APEY was synthesized in laboratory. AA and PAYS were characterized by FT-IR and 1H-NMR, which suggest that APEY and PAYS were synthesized successfully. Thermo gravimetric Analysis (TGA) reveal that PAYS is more stable than APEY. The influence of monomer ratio, initiator amount, reaction temperature, reaction time and chain transfer amount on inhibitory capacity was investigated, and the optimal technological process was determined.The effectiveness of PAYS against scales deposition and disperse the ferric oxide were determined according to the national standard by the static scale inhibition test. The rotary coupon corrosion instrument also measured anti-corrosion property. Experimental data showed that the terpolymer was a high-efficient anti-scaling, dispersion and anti-corrosion, and it nearly 81.2% at the dosage of 12mg/L for calcium carbonate and 100% at the dosage of 5mg/L for calcium sulfate under the best synthesis process. It exhibited excellent ability for calcium orthophosphate, with approximately 100% efficiency at the dosage of 6mg/L, as well as high efficiency toward barium sulfate scales nearly 75.4% inhibition at the dosage of 20mg/L. In addition, it has good effect on controlling iron (III) scaling and the minimum value of solution transmittance 13.2% using 7mg/L. PAYS is also a excellent cathode corrosion inhibitor, the maximum anti-corrosion ratio 77.5% is gained at the amount of 40 mg/L. The inhibition of PAYS was compared with commercial water treatments, and the results reveal that it is an outstanding scale inhibitor.The formation of scale precipitates was characterized by SEM, TEM and XRD. It appeared that the crystal shape, size, and the morphology of scale changed apparently at the presence of PAYS. This study was also devoted to the understanding of the action mechanism of these inhibitors in suppressing the crystal nucleus formation and preventing the crystal growth. Based on the contrast experiment of scale formation, the supposing mechanism diagram was also delineated and analyzed in detail.